FAST FOURIER TRANSFORM PROCESSOR IN AN OFDM SYSTEM AND A FAST FOURIER TRANSFORM METHOD IN AN OFDM SYSTEM FOR MINIMIZING POWER CONSUMPTION AND AN IMPLEMENTATION SPACE OF AN FFT BLOCK

摘要

PURPOSE: A fast fourier transform processor in an OFDM system and a fast fourier transform method in an OFDM system are provided to use an Radix-42 algorithm, a CSD(Canonic Signed Digit) mode, and a CSS(Common Sub-expression Sharing) mode.;CONSTITUTION: A FFT(Fast Fourier Transform) processor includes three or more stages. The processor performs FFT(Fast Fourier Transform) operation by using an Radix-42 DIF algorithm. Each stage includes butterflies(120,220,324) consisting of addition blocks(122,222) and multiplication blocks(124,224) and delay transformers(110,210,310). The processor performs the butterfly operation by using a CSD(Canonic Signed Digit) coefficient. The processor implements the butterfly operation in a CSS mode by using a adder and a shift.;COPYRIGHT KIPO 2013